A method and/or a driver assistance system and a non-track-bound convoy are discussed in EP 3 091 520 A1.
It is believed to be understood to electronically couple multiple non-track-bound vehicles to one another such that they can travel in succession in largely automated manner at an almost constant, short distance. The distances between respective vehicles traveling in direct succession can in this case be chosen such that the vehicles act similarly to a convoy. At least the second vehicle and the further vehicles in the convoy each have a longitudinally guiding driver assistance system that is active during convoy travel. The vehicles of the convoy are controlled with one another by an electronic control and the longitudinally guiding driver assistance systems such that this automated travel state can be realized without risk.
This type of electronic coupling of vehicles, or this type of control of vehicles, is also described by the terms “platooning”, “automatic convoy travel”, “electronic drawbar” or “road train” in the literature. This can achieve better utilization of the road by virtue of shorter distances between the individual vehicles, a continuous flow of traffic with a lower number or regularity of queues, a lower energy consumption as a result of the aerodynamically beneficial utilization of slipstreams and strain relief for the drivers.
This requires all of the vehicles traveling in the convoy to have the appropriate driver assistance and control systems and also car-to-car communication (C2C). C2C communication stands for car-to-car communication and denotes communication of vehicles among one another. That is to say that the vehicles communicate among one another in order to clarify which vehicle is to follow which vehicle. When traveling in a convoy, the first vehicle or leading vehicle prescribes the speed and direction of travel, and further vehicles follow at a short distance. As a result of the vehicles being networked by car-to-car communication (C2C), they react more quickly in the event of braking maneuvers and can thus keep at a shorter distance from one another than usual.
Using car-to-car communication (C2C), the vehicles involved in traveling in a convoy communicate the control commands and information. In particular, the control commands and information required for the convoy travel mode are passed from the leading vehicle to the following vehicles. Vehicles following the leading vehicle also return data to the leading vehicle. However, the WLAN communication devices based on IEEE 802.11p, or ITS-G5, for which provision is usually made for this purpose are in an as yet incomplete optimization and standardization process with regard to the specific requirements for applications in vehicle safety systems though. Technological challenges for these WLAN communication devices arise particularly as a result of the frequency range used at 5.9 GHz. At this frequency, the attenuation of the signal by the cable used is relatively great. Additionally, the propagation properties of the emitted electromagnetic wave are highly dependent on the location of the arrangement of the antenna.
The demands placed by vehicle systems such as automatic convoy travel on the communication between the vehicles are significantly increased from the point of view of functional safety.
The invention is, by contrast, based on the object of developing a method and a driver assistance system and also a convoy of the type mentioned at the outset such that a high level of security is achieved at low cost.
This object is achieved according to the invention by the features as described herein.